SG, Stomach, Liver, Pancreas Flashcards
1
Q
function of salivary glandsj
A
- produce saliva + release it into mouth
2
Q
what does saliva contain?
A
water, mucus, alkali and the enzyme amylase to break down starch into simpler sugars
3
Q
what happens in te stomach?
A
- mechanical digestion of food by churning
- chem. digestion of protein by pepsin
- gastric juice contains HCl which provides the optimum pH for pepsin to work. it also kills bacteria and harmful microorganisms by denaturing their enzymes
4
Q
pancreas
A
- the pancreas releases three enzymes into the duodenum to help with digestion:
- amylase
- lipase
- protease
5
Q
liver
A
- produces bile which is stored in the gall bladder
- the gall bladder releases bile into the duodenum
6
Q
what do bile salts do?
A
- help to emulsify lipids by breaking large pieces of lipid into smaller droplets to increase their surface area for the chemical digestion of fat to fatty acids + glycerol by lipase
- neutralise the acidic mixture of food and gastric juices entering the duodenum from the stomach to provide a suitable pH for enzyme action in the duodenum.
7
Q
small intestine
A
- produces enzymes for digestion
- absorption of water and digested food occurs hete
8
Q
how is the small intestine adapted for absorption?
A
- very long: higher chance 4 the food molecules to be absorbed into the blood before they reach the large intestine
- has villi which increase surface area over which the food can be absorbed
9
Q
villlus
A
- wall is one layer of cells thick: food molecules can pass quickly and easily through it
- rich network of capillaries: carry water and water-soluble foods (glucose, amino acids, minerals) away quickly
- lacteal: each villus has a structure called a lacteal to absorb fatty acids and glycerol
10
Q
what is the wall of the villus called?
A
epithelium
11
Q
what happens to the digested food?
A
it is taken to the liver, where the liver takes excess glucose from the blood and stores it as glycogen
